I first encountered the No True Scotsman fallacy when I was in college. This was in the early 90’s, right after the collapse of communism. Most people accepted that 70 years of failure had disproved communist ideology. But a few holdout professors insisted that the Soviet Union didn’t really practice communism … real communism had never been tried.

It’s a tempting argument because it allows people to maintain allegiance to a dogma while ignoring its problems. And it is more pervasive than you think. The War on Drugs is an extension of the NTS fallacy because its defenders will always tell you that it hasn’t succeeded only because we haven’t tried hard enough. We haven’t had a true War on Drugs. Problems in public education … or any public program for that matter … are always attributed to underfunding (“we haven’t really funded our public education system”). And Republican stalwarts insist that they haven’t won an election recently because they aren’t nominating “real conservatives” for President.

It is also tempting because it allows soi-disant movement “leaders” to apply ideological purity tests to their own causes and purge views that they don’t like. It allows them to stifle debate on subject that sometimes need it. So “no true conservative” believes in raising taxes. “No true liberal” believes in restricting abortion. “No true libertarian” supports the War on Terror.

The thing is that the No True Scotsman Fallacy, like most fallacies, is a twisted version of a legitimate argument. That argument is, to extend the metaphor, “don’t tell me what Scotsmen are like”. Or, if you prefer, “don’t pretend that Welshman is actually a Scotsman”.

The metaphor is getting away from me, isn’t it? Let’s be more detailed.

People often apply completely inappropriate labels to views they don’t like. As a libertarian-conservative, I find that the libertarian movement is one of the most common victims of these attacks because, to lazy commentators, libertarianism is defined as “whatever it is I don’t like”. Here, for example, a Guardian writer tries to describe the UK Independence Party as “libertarian” despite their anti-immigrant, anti-gay and pro-police stances. These are stances that few knowledgable people would ascribe to the libertarian movement in this country, which specifically calls for ending the War on Drugs, not jailing people for nonviolent crime, open borders and marriage freedom. Last month, the government shutdown was blamed on libertarianism. To be fair, some libertarians supported it. But the chief architect of the shutdown — Ted Cruz — is not a libertarian and would not describe himself as one, being a staunch culture conservative and supporter of the surveillance state.

Balloon Juice has frequently been one of the worst at ascribing bizarre views to libertarians, hilariously bashing Libertarians for ignoring the problems of mass incarceration while Reason was running a full issue on the subject (in fact, libertarians and some conservatives are pretty much the only ones talking about the problems of mass incarceration). Salon has now taken up the hardcore anti-libertarian meme, recently describing libertarianism as

a right-wing political party that opposes all gun control laws and public healthcare, supported the government shutdown, dismisses public education, opposes organized labor, favors the end of Social Security as we know it, and argues in its formal political manifesto that “we should eliminate the entire social welfare system” while supporting “unrestricted competition among banks and depository institutions of all types.

Libertarianism is a broad movement. But that description is a cartoon version that isn’t even close to what most libertarians believe. Many support some gun control laws, many opposed the shutdown, most oppose the public education monopoly not the existence of public schools. Libertarians don’t oppose unions; they oppose the political empowerment that has left governments hundreds of billions in debt. Unrestricted competition among banks mainly means ending bailouts and special dispensations (and many think unrestricted competition may mean breaking up the big banks). And there are many libertarians — including me — who do not oppose the existence of basic social safety net. In fact, many libertarians — most notably Milton Friedman — support replacing the existing welfare system with a negative income tax or guaranteed basic income. The highly successful welfare reform and EITC of the Clinton Era came from these ideas.

We’re not the only victims of this, of course. It has unfortunately become de rigueur in political discourse to take the most extreme views of a movement (or the most extreme views one feels they can lump into a movement) and claim they represent the whole. So when Todd Akin says something stupid about rape, that represents the secret views of a hundred million conservatives. If Rick Santorum opposes birth control, that means all conservatives do. If Cynthia McKinney or Van Jones is a truther, that means a hundred million liberals think Bush conspired to create 9/11. And if you disagree with this assessment and point out that these guys don’t represent the bulk of the movement, “No True Scotsman” is trotted out.

One of the most common subjects about which I get into this is … wait for it … climate change. My feeling is that, while we can debate our response to global warming, conservatives should not pretend that AGW is a hoax. Conservatism is rooted in prudence and basic prudence says we should address a potential global problem even if we’re not 100% sure it’s real. But I’m frequently told that “no true conservative” would believe in climate change because of Algore or Climategate. This, of course, reflects a deeper problem in the conservative movement which is splitting between conservatism — defined as a prudent suspicion of powerful government — and radicalism — defined as an intense opposition to almost all government. This became very visible during the recent shutdown as conservatives called for the shutdown to end while the radicals wanted to keep it going (keep in mind that I don’t regard “radical” as a slur; our Founders were pretty damned radical).

In any case, when one tries to defend a movement from the more marginal views incorrectly attributed to it, the NTS fallacy is frequently thrown down. In short, the “no true Scotsman” fallacy is in danger of becoming a duck blind for making inaccurate ad hominem attacks on political philosophies. It is itself becoming a fallacy.

My professors were wrong about communism. They were not wrong because of the NTS Fallacy. They were wrong because the Communist countries did pursue the policies advocated by Marx and Lenin. They were wrong because Communism did require Gulags and thought control, as Lenin stated. They were wrong because George Orwell — himself a socialist — recognized Communism for what it was and warned us about what it was and what it would do. They were wrong because the policies they were advocating were those that had been pursued in communist countries. And they were wrong because many of them either ignored or sugarcoated the horrific abuses of the Communists (and many still do).

There are Republicans who oppose legal birth control. This does not reflect the majority of the conservative movement. Not because “no true conservative” opposes birth control but because almost all Americans, including vast majorities of conservatives, believe that birth control should be legal. There are libertarians who supported the War on Terror or restrictive immigration laws (Neal Boortz, in particular). But most do not and only a few subscribe to anything close to the racial views promulgated by such as Lew Rockwell.

Politics needs to be about ideas, not identity. To return to my opening quote: who cares if “no true Scotsman” put sugar in his porridge? What matter is if sugar in porridge is a good idea (note: it is). What matters is that people stop dismissing the ideas of Scotsmen because one happens to put anchovies in his porridge.